Beech bark disease: mortality due to infection of beech trees and subsequent forest succession at Colonial Point Memorial Forest, Michigan

Abstract

Among forest pathologens, Beech Bark Disease (BBD) is unique in having a two-part attack on the American beech (Fagus grandifolia) by the beech scale insect and an invasive fungus. Interactions between beech scale and fungus have led to widespread beech mortality as populations are increasingly infected. A previous study on Colonial Point Memorial Forest beech populations in 2012 by the University of Michigan Biological Station (UMBS) established two plots of beech trees to be monitored temporally for the effects of BBD. This study examined the percent mortality of this beech population with respect to level of BBD infection and the status of forest succession as beech are eradicated. High levels of mortality were found, with one plot exhibiting significantly greater mortality, perhaps related to higher levels of infection in 2012. Species richness of sapling swas comparable between beech plots despite differing beech mortality. Continued monitoring of beech trees infected with BBD is critical for the understanding and conservation of populations threatened with extirpation.